The therapy of degenerative diseases of the lumbar spine involves medical and socioeconomic problems. In the course of lumbar disk herniations, in progressive pain conditions or neurological deficits, a surgical procedure may be necessary after exhausting conservative measures. Despite good therapeutic results of conventional operations, damage can arise as a consequence of traumatisation. Therefore it is especially important to continuously optimize this procedure. Minimally invasive techniques can reduce tissue injuries and their consequences. Endoscopic operations show advantages that make this method the standard procedure in many areas. Lumbar transforaminal procedures with posterolateral access have been performed for more than 20 years. In this case the working field is located predominantly intradiscally as well as intraforaminally and extraforaminally.